In general, unlike a primary battery, research into a secondary battery, which may be charged and discharged and may be applied to various fields, such as a digital camera, a cellular phone, a notebook computer, and a hybrid car, has been actively conducted. An example of the secondary battery may include a nickel-cadmium battery, a nickel-metal hybrid battery, a nickel-hydrogen battery, and a lithium secondary battery.
Further, as a power source for an electric car or a hybrid car, the lithium secondary battery has been mainly used. Herein, since large power is required to drive a motor, and the like is required, a large-capacity battery pack in which a plurality of high-output battery cells or cell modules are connected to each other in series is generally used.
As described above, the battery pack is generally configured to include the plurality of battery cells which are connected to each other in series. In particular, in the case of the battery pack for the hybrid car, as several to several tens of battery cells are alternately charged and discharged, there is a need to keep and manage the battery in an appropriate operation state by controlling the charging and discharging, and the like.
Further, the battery pack has the plurality of battery cells disposed therein and the electrode tabs of each battery cell are electrically connected to each other by the connectors and the connectors are connected to protection circuits through the voltage sensing circuits so as to measure voltages of each electrode cell.
However, the battery pack according to the related art does not have a protector to block an overcurrent flowing in the voltage sensing lines, the protection circuits, and the like, in which the overcurrent protector may be damaged or short-circuited during a disposition operation of the voltage sensing lines even though the overcurrent protector is formed in the voltage sensing line.
Further, a technology of blocking an overcurrent from introduced into the battery pack according to the related art is disclosed and FIG. 1 illustrates the battery pack according to the related art.
The battery pack according to the related art is configured to include a case 10, an electrode plate assembly which is disposed in the case 10 and generates electric energy by an electrochemical reaction and includes a positive electrode plate, a negative electrode plate, and a separator, a positive electrode connection member 21 which is electrically connected to the positive electrode plate of the positive electrode plate assembly 20 to be delivered to a positive electrode terminal 30, and a negative electrode connection member which is electrically connected to the negative electrode plate of the electrode plate assembly to deliver the electric energy to a negative electrode terminal 40.
In this case, the fuses 50 may be detached and attached between the positive electrode terminal 30 and the positive electrode connection member 21 or between the negative electrode terminal 40 and the negative electrode connection member, such that the damage of the battery pack due to the short circuiting of the electrode plate assembly or the introduction of the overcurrent may be prevented.
However, the battery pack according to the related art as described above has a complicated structure and thus is not easily manufactured and a contact part between the positive electrode connection member 21 and the fuse 50 or the positive electrode terminal 30 and the fuse 50 is separated from each other due to vibration or impact and thus the short-circuiting therebetween may occur.
Further, since the fuse 50 is connected to the electrode terminals 30 and 40, the fuse does not serve to protect each cell when short-circuiting or abnormality occurs in each cell of the electrode plate assembly 20.